The newest version of the Do-More Designer Programming Software (2.9) includes a Modbus I/O Scanner. This Modbus scanner will simplify Modbus RTU serial communications to any device. Communications are done independent of the PLC scan time and will have little or no ladder logic for the program.
We will be communicating to a Solo process temperature controller via Modbus RTU RS485. (twisted pair) Setting up the Modbus IO scanner and reading the present value (PV) and set value (SV) of the Solo. We will also write the set value (SV) located within the BRX Do-More controller. Communications will happen without using any ladder logic code. Let’s get started. Continue Reading!
All Solo Standard Process Temperature Controllers that support RS-485 serial communications can use the SL-SOFT configuration and monitoring software. This free package will communicate to monitor multiple SOLO controllers using Modbus RTU or Modbus ASCII protocols.
We will be installing the SL-SOFT configuration and monitoring software package on our Windows 10 PC. Communicating through our Waveshare USB to RS485 adapter, Modbus RTU will be used as the protocol to establish communication. Let’s get started. Keep on Reading!
The productivity suite software now contains a plc simulator. The software is a free download and is available from automation direct. This software will now allow you to test or troubleshoot your program without the physical hardware present. The entire family of controllers can use the simulator. P1000, P2000, and P3000 emulation can happen on the following parts of the productivity series hardware:
– P1000 CPU’s and local I/O stack, P2000 and P3000 CPU’s and local bases
– All basic I/O modules, both analog and digital
– Modbus TCP Server/Client connections on external Ethernet port
The simulation mode is available on the Productivity Suite version 3.8.x.x or higher. We will be discussing the PAC (Programmable Automation Controller) PLC Simulator. Testing this simulator will be done using our first program (Start-Stop Circuit) and the PID instruction in our Productivity 1000 series. We will also be connecting to physical hardware after using our simulator to test the program. Let’s get started. Keep on Reading!
A Proportional-Integral-Derivative algorithm is a generic Control Loop feedback formula widely used in industrial control systems. A PID algorithm attempts to correct the error between a measured process variable and the desired setpoint by calculating and then outputting a corrective action that can adjust the process accordingly and rapidly, to keep the Error to a minimum.
The following links will explain the PID instruction.
PID for Dummies
PID Theory Explained
Wikipedia PID Controller
We will be using an immersion heater in a cup of water to keep the temperature at a constant value.
Our immersion heater will be controlled through a relay using time proportional control from our PID output. A J type thermocouple will be used with the P1-04THM thermocouple temperature and voltage input module. The Arduino PID Library by Brett Beauregard will be used with our productivity open P1AM industrial arduino. Our program sketch will use productivity blocks, that will then be verified into the C++ code in the Arduino IDE. Let’s get started. Continue Reading!